Jupyter notebook : config toolbar for choosing latex environments is missing

Hello community,
I recently removed anaconda from my computer and replaced it with miniconda.
I reinstalled jupyter and also nb extensions. This works well, except for one particular nbextension : Latex environments.

Notwithstanding that I strictly followed the installation procedure regarding the use of latex environments in the nbextensions and that I checked the box “LaTeX_envs menu (insert environments)” , this does not show up.
I’m able to manually write in a markdown cell equations with \begin{equation},
but no longer {itemize} for example.
I include a pic. of the documentation file latex_env_doc.ipynb which visualises the problem.
Can someone give me a hint to solve this ?